Re: MIN/MAX functions for a record
От | Tom Lane |
---|---|
Тема | Re: MIN/MAX functions for a record |
Дата | |
Msg-id | 906076.1711120375@sss.pgh.pa.us обсуждение исходный текст |
Ответ на | Re: MIN/MAX functions for a record (Aleksander Alekseev <aleksander@timescale.com>) |
Ответы |
Re: MIN/MAX functions for a record
|
Список | pgsql-hackers |
Aleksander Alekseev <aleksander@timescale.com> writes: >> In my queries I often need to do MIN/MAX for tuples, for example: >> SELECT MAX(row(year, month)) >> FROM (VALUES(2025, 1), (2024,2)) x(year, month); >> This query throws: >> ERROR: function max(record) does not exist >> Was this ever discussed or is there something preventing the implementation? > I believe it would be challenging to implement max(record) that would > work reasonably well in a general case. As long as you define it as "works the same way record comparison does", ie base it on record_cmp(), I don't think it would be much more than a finger exercise [*]. And why would you want it to act any differently from record_cmp()? Those semantics have been established for a long time. regards, tom lane [*] Although conceivably there are some challenges in getting record_cmp's caching logic to work in the context of an aggregate.
В списке pgsql-hackers по дате отправления: